package com.evil.Utils;

import Decoder.BASE64Decoder;
import Decoder.BASE64Encoder;

import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;


/**
 * AES 是一种可逆加密算法，对用户的敏感信息加密处理 对原始数据进行AES加密后，在进行Base64编码转化；
 */
public class Encryp_AES
{
    /*
     * 加密用的Key 可以用26个字母和数字组成 此处使用AES-128-CBC加密模式，key需要为16位。
     */
    private String sKey = "evil171469824555";//key，可自行修改
    private String ivParameter = "0692038203940329";//偏移量,可自行修改
    private static Encryp_AES instance = null;


    public static void main(String[] args) throws Exception
    {
        // 需要加密的字串
        String cSrc = "123456";

        // 加密
        long lStart = System.currentTimeMillis();
        String enString = Encryp_AES.getInstance().encrypt(cSrc);
        System.out.println("加密后的字串是：" + enString);

        long lUseTime = System.currentTimeMillis() - lStart;
        System.out.println("加密耗时：" + lUseTime + "毫秒");
        // 解密
        lStart = System.currentTimeMillis();
        String DeString = Encryp_AES.getInstance().decrypt(enString);
        System.out.println("解密后的字串是：" + DeString);
        lUseTime = System.currentTimeMillis() - lStart;
        System.out.println("解密耗时：" + lUseTime + "毫秒");
    }

    /**
     * 加密
     *
     * @return
     */
    public static String getAESCode(String content)
    {
        String enString = "";
        try
        {
            enString = Encryp_AES.getInstance().encrypt(content);
        }
        catch (Exception e)
        {
            e.printStackTrace();
        }
        return enString;
    }

    /**
     * 解密
     *
     * @return
     */
    public static String setAESCode(String content)
    {
        String deString = "";
        try
        {
            deString = Encryp_AES.getInstance().decrypt(content);
        }
        catch (Exception e)
        {
            e.printStackTrace();
        }
        return deString;
    }


    private Encryp_AES()
    {

    }

    private static Encryp_AES getInstance()
    {
        if (instance == null)
        {
            instance = new Encryp_AES();
        }
        return instance;
    }

    private static String Encrypt(String encData, String secretKey, String vector) throws Exception
    {

        if (secretKey == null)
        {
            return null;
        }
        if (secretKey.length() != 16)
        {
            return null;
        }
        Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
        byte[] raw = secretKey.getBytes();
        SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");
        IvParameterSpec iv = new IvParameterSpec(vector.getBytes());// 使用CBC模式，需要一个向量iv，可增加加密算法的强度
        cipher.init(Cipher.ENCRYPT_MODE, skeySpec, iv);
        byte[] encrypted = cipher.doFinal(encData.getBytes("utf-8"));
        return new BASE64Encoder().encode(encrypted);// 此处使用BASE64做转码。
    }


    // 加密
    private String encrypt(String sSrc) throws Exception
    {
        Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
        byte[] raw = sKey.getBytes();
        SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");
        IvParameterSpec iv = new IvParameterSpec(ivParameter.getBytes());// 使用CBC模式，需要一个向量iv，可增加加密算法的强度
        cipher.init(Cipher.ENCRYPT_MODE, skeySpec, iv);
        byte[] encrypted = cipher.doFinal(sSrc.getBytes("utf-8"));
        return new BASE64Encoder().encode(encrypted);// 此处使用BASE64做转码。
    }

    // 解密
    private String decrypt(String sSrc) throws Exception
    {
        try
        {
            byte[] raw = sKey.getBytes("ASCII");
            SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");
            Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
            IvParameterSpec iv = new IvParameterSpec(ivParameter.getBytes());
            cipher.init(Cipher.DECRYPT_MODE, skeySpec, iv);
            byte[] encrypted1 = new BASE64Decoder().decodeBuffer(sSrc);// 先用base64解密
            byte[] original = cipher.doFinal(encrypted1);
            String originalString = new String(original, "utf-8");
            return originalString;
        }
        catch (Exception ex)
        {
            return null;
        }
    }

    private String decrypt(String sSrc, String key, String ivs) throws Exception
    {
        try
        {
            byte[] raw = key.getBytes("ASCII");
            SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");
            Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
            IvParameterSpec iv = new IvParameterSpec(ivs.getBytes());
            cipher.init(Cipher.DECRYPT_MODE, skeySpec, iv);
            byte[] encrypted1 = new BASE64Decoder().decodeBuffer(sSrc);// 先用base64解密
            byte[] original = cipher.doFinal(encrypted1);
            String originalString = new String(original, "utf-8");
            return originalString;
        }
        catch (Exception ex)
        {
            return null;
        }
    }

    private static String encodeBytes(byte[] bytes)
    {
        StringBuffer strBuf = new StringBuffer();

        for (int i = 0; i < bytes.length; i++)
        {
            strBuf.append((char) (((bytes[i] >> 4) & 0xF) + ((int) 'a')));
            strBuf.append((char) (((bytes[i]) & 0xF) + ((int) 'a')));
        }

        return strBuf.toString();
    }


}